The invention was made in part with U.S. Government support under contract number NO1-HD-8-2917, awarded by the National Institute of Child Health and Human Development (NICHD). Therefore, the U.S. Government has certain rights in the invention.
Isolation of nucleic acids and proteins from electrophoresis gels has been performed according to methods available in the prior art. For example, nucleic acids have been recovered from agarose or acrylamide gels by methods such as diffusion, extrusion by compression or crushing of the gel coupled with glass bead recovery, gel dissolution followed by chemical extraction, and electro-elution. Electro-elution is the elution of a charged molecule from a matrix by movement of that molecule within an electric field. Electro-elution methods of the prior art include elution in an electric field onto, e.g., DEAE paper, or into a dialysis membrane. Recovery of the eluted molecule from the paper or membrane may be difficult due to irreversible binding, and may result in degradation, contamination or loss of the end product.
Prior art electro-elution methods also may result in selective recovery of molecules based on size, charge, or other properties. Such methods are particularly inefficient where the sample includes only a minute amount of the biological molecule. Furthermore, transfer of the eluted product from the paper or membrane to a concentrator, or concentration of the product from a relatively large volume involves the risk of loss of the end product. Simultaneous processing of multiple samples, e.g., hundreds, according to prior art electro-elution methods, is difficult and cumbersome.
It is an object of the invention to provide for selective recovery of charged molecules from impure samples such as body fluids. Another object is to provide for highly quantitative recovery of biological molecules. Another object of the invention is to allow for recovery of biological molecules from a number of samples simultaneously, thus saving time and effort and providing for subsequent simultaneous processing of the samples. Yet another object of the invention is to provide for simultaneous recovery of exceedingly small amounts of biological molecules from multiple samples. Another object of the invention is to avoid the risk of loss of the eluted product by providing an end product preparation which does not require concentration from a large volume or, in some diagnostic assays, does not require further purification after electro-elution.